In the semiconductor industry, there is a continuing trend toward higher device densities. To achieve these high device densities there have been, and continue to be, efforts toward scaling down device dimensions (e.g., at sub-micron levels) on semiconductor wafers. In order to accomplish such densities, smaller feature sizes and more precise feature shapes are required. This may include width and spacing of interconnecting lines, spacing and diameter of contact holes, and surface geometry, such as corners and edges, of various features. The dimensions of and between such small features can be referred to as critical dimensions (CDs). Reducing CDs and reproducing more accurate CDs facilitates achieving higher device densities.
Today's standard packaging densities can tolerate over a kilometer of metallic interconnects in a single chip, which can result in delays that can be substantial when considering the speeds at which modern integrated circuits perform activities. For example, delays can be a result of parasitic capacitance, which can increase as CD decreases between pattern lines on a wafer. Additionally, electromigration can cause a significant number of problems in conventional integrated chips, such as, for example, open circuits caused by voids of metal atoms, and short-circuits between lines caused by an overabundance of metal atoms that he migrated to an undesirable region.
Such wafer defects have prompted wafer fabrication facilities to initiate wide-spread process controls in an attempt to mitigate wafer defects and increase wafer throughput. Currently, wafer fabrication facilities monitor thousands of wafer parameters in order to achieve the above-mentioned goals. Accordingly, control protocols, such as wafer level reliability (WLR) testing, continue to gain popularity as process controls for identifying potential factors that can detrimentally affect device reliability. However, there remains an unmet need in the art for systems and methods that improve efficiency and speed in wafer fabrication while reducing production costs.